Liver and/or lung metastasectomy after cetuximab or bevacizumab+FOLFIRI chemotherapy in patients (pts) with metastatic colorectal cancer (mCRC).

Abstract

843 Background: Some mCRC pts who have liver and/or lung metastases (LLMs) could achieve cure after palliative chemotherapy and conversion surgery (CS) including metastasectomy. Though targeted agents including bevacizumab and cetuximab significantly improved outcomes in mCRC pts, the effect of targeted agents on cure rate after CS has not yet been thoroughly investigated. Methods: We analyzed clinical data of mCRC pts who initially had unresectable LLMs regardless of their size and number and underwent first-line cetuximab or bevacizumab+FOLFIRI. Pts who had metastasis other than liver and lung were excluded. Results: From January 2013 to May 2016, 87 pts (male, 56) were consecutively enrolled: liver-limited metastasis in 42 pts (48.3%), lung-limited metastasis in 17 pts (19.5%), and both liver and lung metastases in 28 pts (32.2%). Median age was 62 years (range, 37-85). K-RAS or N-RAS mutation was detected in 39 pts (46.4%) and B-RAF in 2 pts (3.1%) among mutation evaluated pts. Among them, 35 pts (40.2%) received cetuximab+FOLFIRI and the others (N = 52, 59.8%), bevacizumab+FOLFIRI. Median follow-up time was 20.0 months (range, 1.9-49.1). Response rate was 65.7% in the cetuximab group (CET) and 42.3% in the bevacizumab group (BEV) ( p= 0.032). Median progression-free survival was 19.1 months (95% confidence interval [CI], 11.2-27.1) in CET and 14.1 months (95% CI, 11.5-16.8) in BEV ( p= 0.249). CS was performed in 24 pts (27.6%) after median 8.7 months (range, 2.5-27.3) after initiation of chemotherapy. In CET, 11 pts (31.4%) including 8 pts with partial response (PR) and 3 pts with stable disease (SD) underwent CS and all (100%) attained R0. In BEV, 13 pts (25%) including 6 pts with PR and 7 pts with SD received CS and 11 of them (84.6%) achieved R0. Among pts with R0 resection, median disease-free survival (DFS) was 8.8 months (95% CI, 4.9-12.7) in CET and 3.2 months (95% CI, 0.0-7.4) in BEV ( p= 0.326). Conclusions: A substantial proportion of pts could receive CS after cetuximab or bevacizumab+FOLFIRI chemotherapy. CET tended to show higher rate of CS. However, the median DFS after R0 resection was not significantly different between the two groups.